Rapid and accurate focusing telephoto lens structure
By setting the lens assembly and aperture to move synchronously, combined with a motor-driven focusing ring and aperture, the problem of long focusing time and inaccuracy of telephoto lenses is solved, achieving fast and accurate focusing.
Patent Information
- Application Number
- CN202423187789.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-24
- Publication Date
- 2025-10-31
- Estimated Expiration
- 2034-12-24
AI Technical Summary
Existing telephoto lenses have long focusing times and are not precise enough, making it impossible to quickly achieve high-resolution imaging.
By setting the telephoto lens assembly to move simultaneously with the aperture stop, focusing is achieved through the rotation of guide pins and slots, and automatic adjustment is achieved by combining the motor-driven focusing ring and aperture stop, thus realizing the synchronous movement of the lens and aperture stop.
It achieves a fast and accurate focusing process, improving imaging speed and resolution.
Smart Images
Figure CN223501240U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of lens technology, specifically to a telephoto lens structure for fast and accurate focusing. Background Technology
[0002] Existing telephoto lenses are basically Figure 1 The structure shown adopts a half-group compensation method. The fixed group A is fixed and the aperture position is fixed. Focusing is completed only by adjusting the compensation group B to move back and forth along the optical axis, thereby achieving high-resolution imaging for close-range detection.
[0003] This method of focusing by adjusting only compensation group B usually requires a longer focusing time and the focus may not be accurate enough. Summary of the Invention
[0004] The technical problem to be solved by this utility model is to provide a telephoto lens structure that can focus quickly and accurately. By setting the telephoto lens assembly and the aperture stop to rotate simultaneously through the cooperation of guide pins and slots, focusing can be achieved. Since the entire lens assembly and the aperture stop move at the same time, focusing is fast and accurate.
[0005] This utility model is implemented as follows:
[0006] A telephoto lens structure for fast and accurate focusing includes:
[0007] A first meniscus lens, a first cemented lens, a second cemented lens, a second meniscus lens, a third cemented lens, and a third meniscus lens are arranged sequentially from the object plane to the image plane. The first meniscus lens and the first cemented lens form the front fixed group, and the second cemented lens, the second meniscus lens, the third cemented lens, and the third meniscus lens form the rear fixed group.
[0008] An aperture is positioned between the front fixed group and the rear fixed group;
[0009] The frame, front fixing group, aperture, and rear fixing group are all fixed inside the frame; guide pins are provided on the outside of the frame.
[0010] The main tube is located outside the frame and has an axial cam groove;
[0011] A rotating ring is located on the outside of the front side of the main tube and has an inclined groove. The guide pin passes through the axial cam groove and the inclined groove in sequence. The guide pin moves axially in the axial cam groove through the inclined groove of the rotating ring, thereby causing the lens frame to move the front fixed group, aperture and rear fixed group back and forth relative to the main tube at the same time to achieve focusing.
[0012] Furthermore, it also includes a focusing ring, which is fixedly connected to the rotating ring, and the rotating ring is driven to rotate by rotating the focusing ring.
[0013] Furthermore, it also includes a first motor for driving the focusing ring to rotate in both directions to achieve automatic focusing.
[0014] Furthermore, the first motor drives the focusing ring to rotate in both directions via a focusing cam.
[0015] Furthermore, it also includes a second motor, connected to the aperture, for automatically adjusting the aperture.
[0016] Furthermore, it also includes an interface for connecting to the camera body.
[0017] Furthermore, the air gap between the first meniscus lens and the first cemented lens is 0.25 mm, the air gap between the first cemented lens and the second cemented lens is 7.95 mm, the air gap between the second cemented lens and the second meniscus lens is 0.85 mm, the air gap between the second meniscus lens and the third cemented lens is 0.35 mm, and the air gap between the third cemented lens and the third meniscus lens is 8.85 mm.
[0018] Furthermore, a first spacer is provided between the first meniscus lens and the first cemented lens, a second spacer is provided between the second cemented lens and the second meniscus lens, a third spacer is provided between the second meniscus lens and the third cemented lens, and a fourth spacer is provided between the third cemented lens and the third meniscus lens.
[0019] Furthermore, the air gap between the third meniscus lens and the imaging plane ranges from 9.18 to 15.28 mm.
[0020] Furthermore, the object-side surface of the first cemented lens is convex, and the image-side surface is concave; the object-side surface of the second cemented lens is concave, and the image-side surface is convex; both the object-side surface and the image-side surface of the third cemented lens are convex.
[0021] The advantages of this utility model are:
[0022] Telephoto imaging is achieved by setting up a front fixed group consisting of a first meniscus lens and a first cemented lens, and a rear fixed group consisting of a second cemented lens, a second meniscus lens, a third cemented lens, and a third meniscus lens. At the same time, the front and rear fixed groups and the aperture are all fixed on the lens frame. By rotating the guide pins and slots, the telephoto lens assembly and the aperture move back and forth relative to the main tube simultaneously, thereby achieving focusing. Since the entire lens assembly and the aperture move simultaneously, focusing is fast and accurate. Attached Figure Description
[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0024] Figure 1 This is a schematic diagram of the optical structure of a telephoto lens in the prior art;
[0025] Figure 2 This is a cross-sectional schematic diagram of the lens structure according to an embodiment of the present utility model.
[0026] Figure 3 This is a side view of the lens structure in an embodiment of the present invention. Detailed Implementation
[0027] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings and specific embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.
[0028] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0029] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0030] Please see Figure 2 and Figure 3 As shown, this utility model provides a telephoto lens structure for fast and accurate focusing, comprising:
[0031] The first meniscus lens 1, the first cemented lens 2, the second cemented lens 3, the second meniscus lens 4, the third cemented lens 5, and the third meniscus lens 6 are arranged sequentially from the object plane to the image plane. The first meniscus lens 1 and the first cemented lens 2 form the front fixed group, and the second cemented lens 3, the second meniscus lens 4, the third cemented lens 5, and the third meniscus lens 6 form the rear fixed group.
[0032] In one specific embodiment, the air gap between the first meniscus lens 1 and the first cemented lens 2 is 0.25 mm, the air gap between the first cemented lens 2 and the second cemented lens 3 is 7.95 mm, the air gap between the second cemented lens 3 and the second meniscus lens 4 is 0.85 mm, the air gap between the second meniscus lens 4 and the third cemented lens 5 is 0.35 mm, and the air gap between the third cemented lens 5 and the third meniscus lens 6 is 8.85 mm. The air gap between the third meniscus lens 6 and the imaging plane ranges from 9.18 to 15.28 mm. The object-side surface of the first cemented lens 2 is convex, and the image-side surface is concave; the object-side surface of the second cemented lens 3 is concave, and the image-side surface is convex; both the object-side surface and the image-side surface of the third cemented lens 5 are convex. The parameters of all lenses are as follows:
[0033]
[0034] Aperture 7 is disposed between the front fixing group and the rear fixing group;
[0035] The frame 8, the front fixing group, the aperture 7, and the rear fixing group are all fixed inside the frame 8; guide pins 9 are provided on the outside of the frame 8.
[0036] The main tube 10 is located outside the frame 8 and is provided with an axial cam groove 11;
[0037] A rotating ring 12 is disposed on the outer side of the front side of the main cylinder 10 and is provided with an inclined groove 13; for example Figure 3 As shown, the guide pin 9 is sequentially inserted into the axial cam groove 11 and the inclined groove 13. The guide pin 9 is driven to move axially in the axial cam groove 11 by the inclined groove 13 of the rotating ring 12, thereby causing the lens frame 8 to move back and forth relative to the main tube 10 at the same time to achieve focusing.
[0038] In one possible implementation, a focusing ring 14 is also included, which is fixedly connected to the rotating ring 12, and the rotating ring 12 is driven to rotate by rotating the focusing ring 14.
[0039] Preferably, it also includes a first motor 15 for automatically focusing by driving the focusing ring 14 to rotate in both directions via the focusing cam 16.
[0040] Preferably, it also includes a second motor 17 connected to the aperture 7 for automatically adjusting the aperture.
[0041] Specifically, it also includes an interface 18 for connecting to the camera body. A first spacer 19 is provided between the first meniscus lens 1 and the first cemented lens 2, a second spacer 20 is provided between the second cemented lens 3 and the second meniscus lens 4, a third spacer 21 is provided between the second meniscus lens 4 and the third cemented lens 5, and a fourth spacer 22 is provided between the third cemented lens 5 and the third meniscus lens 6.
[0042] The lens in this embodiment has a focal length of f35mm, an aperture of F1.8, and features motorized focusing and a P-aperture. Image size: 1.1".
[0043] The working principle of this utility model is as follows:
[0044] Telephoto imaging is achieved by setting a front fixed group consisting of a set of meniscus lenses and cemented lenses on the object side of the aperture 7, and a rear fixed group consisting of two sets of meniscus lenses and cemented lenses on the image side of the aperture 7. Rotating the focusing ring 14 drives the rotating ring 12, causing the inclined groove 13 of the rotating ring 12 to move the guide pin 9 axially within the axial cam groove 11. This allows the lens frame 8 to move the front fixed group, aperture 7, and rear fixed group simultaneously relative to the main tube 10, achieving fast and accurate focusing. The first motor 15 drives the focusing ring 14 to rotate in both directions via the focusing cam 16 to achieve automatic focusing. The second motor 17 is connected to the aperture 7 to achieve automatic aperture adjustment.
[0045] This invention achieves telephoto imaging by setting up a front fixed group consisting of a first meniscus lens and a first cemented lens, and a rear fixed group consisting of a second cemented lens, a second meniscus lens, a third cemented lens, and a third meniscus lens. At the same time, the front and rear fixed groups and the aperture are all fixed on the lens frame. By rotating the guide pins and slots, the telephoto lens assembly and the aperture move back and forth relative to the main tube simultaneously, thereby achieving focusing. Since the entire lens assembly and the aperture move simultaneously, focusing is fast and accurate.
[0046] While specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and not intended to limit the scope of the present invention. Equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the present invention should be covered within the scope of protection of the claims of the present invention.
Claims
1. A telephoto lens structure for fast and accurate focusing, characterized in that, include: A first meniscus lens, a first cemented lens, a second cemented lens, a second meniscus lens, a third cemented lens, and a third meniscus lens are arranged sequentially from the object plane to the image plane. The first meniscus lens and the first cemented lens form the front fixed group, and the second cemented lens, the second meniscus lens, the third cemented lens, and the third meniscus lens form the rear fixed group. An aperture is positioned between the front fixed group and the rear fixed group; The frame, front fixing group, aperture, and rear fixing group are all fixed inside the frame; guide pins are provided on the outside of the frame. The main tube is located outside the frame and has an axial cam groove; A rotating ring is located on the outside of the front side of the main tube and has an inclined groove. The guide pin passes through the axial cam groove and the inclined groove in sequence. The guide pin moves axially in the axial cam groove through the inclined groove of the rotating ring, thereby causing the lens frame to move the front fixed group, aperture and rear fixed group back and forth relative to the main tube at the same time to achieve focusing.
2. The lens structure according to claim 1, characterized in that: It also includes a focusing ring, which is fixedly connected to the rotating ring, and the rotating ring is driven to rotate by rotating the focusing ring.
3. The lens structure according to claim 2, characterized in that: It also includes a first motor, which drives the focusing ring to rotate in both directions to achieve automatic focusing.
4. The lens structure according to claim 3, characterized in that: The first motor drives the focusing ring to rotate in both directions via a focusing cam.
5. The lens structure according to claim 1, characterized in that: It also includes a second motor, connected to the aperture, for automatically adjusting the aperture.
6. The lens structure according to claim 1, characterized in that: It also includes an interface for connecting to the camera body.
7. The lens structure according to claim 1, characterized in that: The air gap between the first meniscus lens and the first cemented lens is 0.25 mm, the air gap between the first cemented lens and the second cemented lens is 7.95 mm, the air gap between the second cemented lens and the second meniscus lens is 0.85 mm, the air gap between the second meniscus lens and the third cemented lens is 0.35 mm, and the air gap between the third cemented lens and the third meniscus lens is 8.85 mm.
8. The lens structure according to claim 1, characterized in that: A first spacer is provided between the first meniscus lens and the first cemented lens, a second spacer is provided between the second cemented lens and the second meniscus lens, a third spacer is provided between the second meniscus lens and the third cemented lens, and a fourth spacer is provided between the third cemented lens and the third meniscus lens.
9. The lens structure according to claim 1, characterized in that: The air gap between the third meniscus lens and the imaging plane ranges from 9.18 to 15.28 mm.
10. The lens structure according to claim 1, characterized in that: The first cemented lens has a convex object-side surface and a concave image-side surface; the second cemented lens has a concave object-side surface and a convex image-side surface; the third cemented lens has both a convex object-side surface and a convex image-side surface.